Hydrogen is expensive: We paid $16.70 per kilogram, and the Mirai's tank holds 5.6 kg. For those of you not mathematically inclined, that's a $93.52 fill-up if your Mirai is running on fumes. (Bad choice of words, perhaps. Since hydrogen is gaseous, one could say the Mirai always runs on fumes.) From three-quarters of a tank, we paid nearly $75 to fill up. This won't be an issue right away, as the Mirai comes with $15,000 or 3 years' worth of free hydrogen. That's enough for 160 complete fills, and even if the Mirai were to only manage 250 miles per tank, would take you to around 37,500 miles. Hydrogen prices are expected to drop to $6-7/kg by 2024 or 2025, but if that doesn't happen, your 2021 Toyota Mirai could start to feel an awful lot like a 1974 Plymouth Fury.
So, it’s expensive now, but in 2-3 years it is predicted to cost around 30-35 bucks to fill up with H. The price of H is projected to drop by 60%